gpsd-users
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[gpsd-users] NTP for more than two PPS-capable devices


From: Eric S. Raymond
Subject: [gpsd-users] NTP for more than two PPS-capable devices
Date: Wed, 14 Jan 2015 10:04:41 -0500
User-agent: Mutt/1.5.23 (2014-03-12)

Sandor R. Repas <address@hidden>:
> I have just found the solution.
> The gpsd handles the PPS as a different device. Actually, my 3 gps devices 
> were 6 devices in GPSD.
> I have modified the #define NTPSHMSEGS line in the gpsd.h file, and it works 
> now.
> It could be a build option, but I was not able to find it.

I am unclear on why this helped, or if it could have helped at all.

The present ntpshm code seems to be built on the assumption that NTP offers
exactly four shared-memory segments through which devices can report time.

If this limit is real, increasing NTPSHMSEGS doesn't actually get you anywhere,
because NTP won't read any reports put in the higher segments.

If it is not real, how do you know how many segments NTP will support.  Is
there a way to ask it?
-- 
                <a href="http://www.catb.org/~esr/";>Eric S. Raymond</a>



reply via email to

[Prev in Thread] Current Thread [Next in Thread]